Caracterização e avaliação da atividade antiparkinsoniana de extratos de Coffea arabica em linhagens modificadas de Saccharomyces cerevisiae como modelo da doença

Abstract

Parkinson's disease (PD) is a neurodegenerative disease that causes loss of control of muscle movements, causing involuntary tremors. PD is caused by the degeneration of dopaminergic neurons (which produce dopamine) due to the formation of protein aggregates of the alpha-synuclein protein, which can have their action potentiated in an environment of oxidative stress. One of the largest sources of antioxidant substances are plants, due to their wide variety of secondary metabolites that present diverse bioactive properties. In this work, we performed the phytochemical characterization and evaluated the antioxidant activity of extracts of leaves and fruits of Coffea arabica in vitro (DPPH, ABTS and peroxide inhibition index) and in vivo (using the mutant strain S. cerevisiae ∆gtt1). Furthermore, a Parkinsonian strain (S. cerevisiae PD1), which has the gene that encodes the expression of alpha-synuclein, was used to evaluate the potential of the extract against the action of the protein, and the quantification of levodopa present in the extracts was performed by highperformance liquid chromatography. The results obtained indicate that the extract has antioxidant action, with the leaf extract being the most promising, with 500.6 and 188.1 µmol TE . g-1 for the leaf, and 80.7 and 14.1 µmol TE . g-1 for the fruit (by the ABTS and DPPH methods, respectively, results that were replicated in the in the in vivo assay. Regarding the antiparkinsonian activity, no modulating action of the disease by inhibition of alpha-synuclein was evidenced, since the extracts were not able to protect cells against its action. This result indicates that simply having strong antioxidant activity is not enough to inhibit protein toxicity, demonstrating that this toxicity is also provided by other pathways, not only by oxidative stress. However, the leaf extract were considered a good source of levodopa, with the content presented in the leaf extract being 7,02 mg.g-1, thus demonstrating its possible use as an adjuvant in the treatment for PD by supplementing levodopa in the neurotransmitter system.